The economic impact of the “docility” EPD
On sale day, at any auction ring, you could ask each cattle rancher what traits they are looking to add to their herd. Some may be primarily concerned with carcass traits, while others look at production value or perhaps, they’re after a particular phenotype. Rarely, will you hear a rancher that’s prioritizing the “docility” EPD when evaluating black angus cattle in the sale ring. But what if this EPD, reflective of a cattle’s temperament, is being overlooked? A recent peer reviewed article from Oregon State University Extension Service (OSU) highlights the important role management and temperament of cattle play in their production and carcass quality.
There are numerous factors that can be considered stressors on cattle, including human handling, disease, weather events or injury. OSU’s article asserts that an animal with an excitable temperament will produce a more aggressive response when being handled in a corral or out on the range. This is a direct reflection of an animal’s inability to cope, therefore classifying their behavior as a stress response. While this is not a revolutionary observation, the relationship between the stress hormone produced by the animal, cortisol, and a cow’s economic value is.
The study examined cortisol levels in cows, heifers and steers placed in various environments, including feed lots and after events like weaning. In all situations, the animals with calm temperaments had measurably lower levels of cortisol than their peers with excitable or aggressive temperaments. For instance, cows with docile temperaments had an average blood cortisol level of 5.7 ng/mL as compared to their more aggressive counterparts who had an average blood cortisol level of 66.1 ng/mL. Studies show that the average daily gain directly decreases in these excitable cattle. Rather than consuming food or supplements, these animals spend more time alert looking for and responding to factors they consider threats. Not only does this mean less feed intake, but the feed consumed is often going to support their body’s stress response. In fact, elevated cortisol levels actually “stimulate the breakdown of body tissues, such as muscle and fat deposits, in order to release energy and protein to further support the behavioral stress response,” according to OSU. Not only were these cattle’s growth rates negatively impacted, but decreases in carcass quality were also examined. Cattle with excitable temperaments have increased incidences of dark cutters and bruised carcasses, as well as decreased meat tenderness.
Furthermore, cortisol played a role in the breeding and reproductive performance of cows. While we know nutrition, as outlined above, contributes to reproductive success, studies are showing that cortisol directly impacts the physiological mechanisms that govern reproduction. The study highlights “cows with calm temperament have reduced cortisol and greater blood concentrations of luteinizing hormone, the hormone required for puberty establishment and ovulation, compared to temperamental cows.” Not only did heifers with more docile temperaments reach puberty sooner, but cows with docile temperaments had also increased chances of becoming pregnant during breeding season.
A cow’s temperament has direct economic implications. Period. The good news: temperament is moderately heritable. Not only is it something you can breed for, but acclimate and manage your herd to. At Kinger Cattle Company, we devote significant resources to the safe handling and acclimation of our cattle. We’re proud that any rancher can walk through our corrals, or fields alongside our cattle. It’s our hope your herd looks like that too. Let us help you get there - reach out today for more information about our cattle and program.